Thrombolysis for Acute Wake-Up and Unclear-Onset Strokes with Alteplase at 0.6 mg/kg in Clinical Practice: THAWS2 Study

<b><i>Introduction:</i></b> The aim of this study was to determine the safety and efficacy of intravenous (IV) alteplase at 0.6 mg/kg for patients with acute wake-up or unclear-onset strokes in clinical practice. <b><i>Methods:</i></b> This multicenter observational study enrolled acute ischemic stroke patients with last-known-well time &gt;4.5 h who had mismatch between DWI and FLAIR and were treated with IV alteplase. The safety outcomes were symptomatic intracranial hemorrhage (sICH) after thrombolysis, all-cause deaths, and all adverse events. The efficacy outcomes were favorable outcome defined as an mRS score of 0–1 or recovery to the same mRS score as the premorbid score, complete independence defined as an mRS score of 0–1 at 90 days, and change in NIHSS at 24 h from baseline. <b><i>Results:</i></b> Sixty-six patients (35 females; mean age, 74 ± 11 years; premorbid complete independence, 54 [82%]; median NIHSS on admission, 11) were enrolled at 15 hospitals. Two patients (3%) had sICH. Median NIHSS changed from 11 (IQR, 6.75–16.25) at baseline to 5 (3–12.25) at 24 h after alteplase initiation (change, −4.8 ± 8.1). At discharge, 31 patients (47%) had favorable outcome and 29 (44%) had complete independence. None died within 90 days. Twenty-three (35%) also underwent mechanical thrombectomy (no sICH, NIHSS change of −8.5 ± 7.3), of whom 11 (48%) were completely independent at discharge. <b><i>Conclusions:</i></b> In real-world clinical practice, IV alteplase for unclear-onset stroke patients with DWI-FLAIR mismatch provided safe and efficacious outcomes comparable to those in previous trials. Additional mechanical thrombectomy was performed safely in them.